You can earn more money from gambling but You can lose all your money.
the secret is a correct management of money and a good bankroll.
Don't try to get rich from gambling in the short term, so had to use a lot of money to play. it's very risky to lose all your money and I guess that is really hard to make a profit every time because also gambling is a luck. so, it all depends on luck
Luck and sometimes the proper use of brain. Like today we see some people loosing badly on Nadal , why people expect Nadal to win too much, that too when he is out of form. I never bet hence on anything as such, unless for fun.